Reading from a text field in another application's window

Question

Is there a way for a Windows application to access another applications data, more specifically a text input field in GUI, and grab the text there for processing in our own

Answer 1

About how to shield the application to prevent it, you could do many things. One way would be to have a own control to handle text input that build up the text from lets say a couple of labels placed where the text would be, or that draws the text graphically.